/**
 * Copyright (c) 2013-2021 Nikita Koksharov
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.redisson.misc;

import java.util.concurrent.atomic.AtomicInteger;

/**
 *
 * @author Nikita Koksharov
 *
 */
public class AsyncCountDownLatch {

    private final AtomicInteger commandsSent = new AtomicInteger();
    private volatile Runnable callback;

    public void countDown() {
        if (commandsSent.incrementAndGet() == 0) {
            callback.run();
        }
    }

    public void latch(Runnable callback, int count) {
        if (this.callback != null) {
            throw new IllegalStateException("Latch can't be called twice");
        }
        this.callback = callback;
        if (commandsSent.addAndGet(-count) == 0) {
            callback.run();
        }
    }
}
